COLFAX, Wash. — May, with its promise of begonias and bumblebees, threw a curveball at eastern Washington this year — a rare heat wave, followed by a cold snap.

And trouble soon followed.

Swarms of large black carpenter ants peppered the towns of Colfax, Endicott and Albion. Then frost coated farmers’ wheat fields.

At the office of Whitman County extension specialist Steve Van Vleet, phone calls and emails have been filled with questions related to the anomalies.

“When the ants appeared, I barely had time to catch my breath between all the inquiries,” he said.

Most of those ants have disappeared, leaving people to wonder if they’re hiding out and destroying homes the way termites do, he explained. The frost on the wheat has disappeared as well, but not the damage inflicted by it.

“As the wheat matures, I’m hearing from farmers concerned that sections of their fields don’t look right,” said Van Vleet, an agriculture scientist who serves farmers, agricultural businesses and communities in one of the most prolific wheat-growing counties in the United States.

The late-season frost and the hordes of carpenter ants “were visual indications of the unusual weather we had,” he said. The ants descended during the hot sunny days of early May. Then, about a week later, temperatures plummeted and created conditions for frost.

“I talked to a wheat grower who’s been in the area for 30 years who told me he couldn’t recall a May like the one we just had,” Van Vleet said.

Which doesn’t surprise meteorologist Nic Loyd of WSU’s statewide AgWeatherNet data and decision-making system. “May was a very strange weather month,” he said. Records were set for heat, cold and rainfall in certain parts of the state, including eastern Washington.

A six-day heat wave “of almost unprecedented duration” brought temperatures to above 90 degrees (83 in Pullman), Loyd said. Just 10 days later, a cold storm lowered the mercury to below freezing in western Whitman County.

“That’s quite cold for late May,” he said.

It got so cold that frost nipped through swaths of winter wheat, including 233 of the 500 acres belonging to Kenda Hergert near Endicott. Hergert is among the many baffled farmers and residents who have phoned or emailed Van Vleet about fallout from the abnormal weather.

Winter wheat enters dormancy during the cold months and comes back to life in the spring, needing warmth and sun to reboot. A late cold snap can throw the crop’s growth off-kilter, resulting in lower yields or all-out decimation.

Following May’s big chill, Hergert watched in dismay as her wheat “started turning from green to yellowish-brown. It looked horrible,” she said. Some of the wheat heads developed a white tint as well.

“When I saw all those acres go from strong and firm to discolored and drooping, I contacted Steve and said, ‘What the heck happened to it?’ ” she recalled.

Van Vleet and several WSU wheat scientists concluded that a constellation of forces – with late-season frost the most prominent – had stressed a substantial portion of her crop.

“What we didn’t know is whether it would recover,” said Van Vleet.

While Hergert’s wheat may not grow into the gleaming prize that farmers strive for, “most of it appears to be recovering,” she said. “The green color has come back and it’s standing taller.”

“I can live with a dozen acres going bad,” she said. “But 230 acres? I’m a small farmer. It would have been devastating.”

As for the swarms of winged carpenter ants, the abnormally hot weather early in the month ushered them in, said Van Vleet: “On May 4, there were none. By May 6, they were everywhere.”

Strolling around Colfax where he works, he saw scores of the big, black ants crawling on sidewalks, park benches and the sides of buildings. Panicked callers said the bugs were marching across their kitchen floors and counters.

“People were calling and saying, ‘Oh my gosh. Where did all the ants come from? Is my house in jeopardy? How do I make them go away?’” he said.

First off, contrary to what many believe, carpenter ants don’t eat homes. They just take bits of them away.

“Termites eat wood. Carpenter ants hollow it out to make room for their nests,” Van Vleet explained to the multitude of callers.

He also told them that, luckily, the ants didn’t fly into town scouting for premium nesting spots. Instead, they were searching for mates, a yearly ritual that normally extends over a period of weeks.

“With the early burst of hot weather, the matured reproductive ants ventured out to reproduce all at once,” he said. “Afterwards, a queen searches for a nesting site to begin a new colony.”

And if one of those colonies gets built inside a tree stump near a house, carpenter ants are adept at using hoses, stacks of wood and tree branches as highways to slip inside and sneak food, he explained.

In the meantime, Van Vleet still gets an earful about the carpenter ants, the frost and, what else, the weather.

“The climate has been a serious issue this year and Mother Nature has shown us all who the real boss is,” he said, as rain pelted the Palouse and thunder boomed overhead.